Changes to Get Agent chat

the data/dashboardUrl response's property format changed from uri to no format for status 200

the data/updatedAt response's property format changed from date-time to no format for status 200

added the optional property data/messages/items/activities to the response with the 200 status

added the optional property data/messages/items/attachments to the response with the 200 status

added the optional property data/messages/items/author to the response with the 200 status

added the optional property data/messages/items/clientMessageId to the response with the 200 status

added the optional property data/messages/items/research to the response with the 200 status

added the required property data/owner to the response with the 200 status

added the required property data/viewerIsOwner to the response with the 200 status

added the required property data/visibility to the response with the 200 status

endpoint added